Up in the Fells, there are hidden corners where the touch of man sweeps back millennia: a flint axe mass-production factory treacherously perched high amongst scree slopes; stone circles, once remote, now implausibly close to a dual carriageway; droving paths through high, wind-buffeted cols, the top soil swept clean, cobbles and clasts exposed, bleached white against acid black peat cliffs.

Now that the hills are mainly a playground not a workplace, it is feet that denude the old ways, scuffing away thin soils, skittering grit and pebbles down in unseen avalanches, deadly to insects, exposing the bedrock, gritty scars. The paths now snake all over, wriggling and twisting across the land. Yet, still nature claws many back and others still remain indistinct, swallowed by bog, slurped by mires. Elsewhere, clear routes, short only of cats-eyes and white lines, suddenly disappear, like a cul-de-sac, or a bridleway near Dunwich, lost to the land, soaked back in, like litmus. And all paths become indistinct in the frequent mists that ride in from the sea, presaged by whipping winds heralding their ride, or the low clouds, sneakier, that whisper round outcrops and smother the senses, magnets held to internal compasses.

One rock, then the next, then another. This way the cairns arose, by calloused hands mysterious. A fourth, fifth, many more. Primitive pyramids, with no hidden secrets, no golden triangles or intersections of ley lines. No way-marks to the Holy Grail, just heaps of rocks, for navigation.

But it is their profusion that is remarkable, and their beauty. There is no classification, but perhaps one should be attempted. First, there are the wayside markers, 50 rocks, 60 perhaps, in loose, unkempt huddles to the side of the path, rarely retaining their form but slipping like an aged bosom. Little care is given them, but they are the most useful perhaps, illuminating paths lost to the dark of fell-walking befuddlement. And they are everywhere: with heartbeat regularity on long, yomping trails, more strategically placed on steeper rock step paths or scrambles; even, in miniature on exposed traverses, built by hardy head-cases intent on the shortest route to market.

The cols are home to the second sort; the fingerposts, the crossways. Markedly bigger, markedly taller but often ragged, they offer nothing more than a choice of route and are little celebrated. Some are embellished with old iron posts, impaled at assorted angles and oftentimes reburied with hags of peat, more rocks or old boots. They are the old men of the hills, tweed jacketed, teeth and fingers stained from years sucking on a jaunty pipe; hob-nailed boots, thick, green socks, passed down, darned, cussed. Wise though, to the ways of the hills.

Summits attract the acclaim, like a feather-winged moth incandescing in the heat of a naked flame. List tickers and fell baggers think little of them, but to us even-paced plodders they are often the highlight. Distinct from afar, they sharpen the peak, darken it too, give it a clear focus, pull the eye magnetically. They can be a distance marker too, when visible, but typically they conceal their reward until the final steps, slowly niggling into view, bit by bit, teasing. Some cairns are magnificent, built by the dry stone wallsmen, knapped and flush, bulging out from a sturdy base before sweeping into to a domed top, 8 foot up. Most are notable if only for their excess, a sick of stones, hurled on from all sides, splintered and forced into support of their neighbours. Their lichen and moss coats are unevenly worn, forced to readjust as the stones slip and yaw. So heavy, yet impermanent, gravity slowly pulls them to the valley floor.

That’s why I cairn-top. To reassert man’s dominion with the tools of nature. At first it was a mountain witticism, a fell joke. Now there is a more spiritual motive, a spiritual need. One stone, just one, added to the top of the cairn; more if it’s lunch time. Build it up, build it up; help weary travellers and lost souls find their way. Build it up, build it up.